Drug & supplement interaction

1,3-dmaa + Lapatinib

Lapatinib brand name: Tykerb.

No Known Interaction
Medically reviewed by · Updated July 2026 · Pair last verified Sep 20, 2026
The bottom line No known interaction

We found no known interaction between 1,3-dmaa and Lapatinib in our sources. Absence of a documented interaction is not the same as proven safety, and does not guarantee one does not exist. Do not start, stop, or change a medication or supplement based on this page; confirm with your pharmacist or doctor first. Additionally, although there is no interaction, the two are separately associated with some of the same side effects, which would make a new symptom harder to attribute to one or the other.

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Interaction report

1,3-dmaa and Lapatinib

We checked these two against our interaction database. Here is what we found.

No Known Interaction Found

We did not find a documented interaction between Lapatinib and 1,3-dmaa in our sources. This does not guarantee that the combination is completely free of risk — there is often limited research on supplements and herbal products, especially around drug interactions.

If you decide to take both, the practical routine is simple: add one new thing at a time and note the date you started it. If the combination is going to disagree with you, it usually shows in the first days to a couple of weeks — and a start date turns “I’ve been feeling off” into something a pharmacist can actually work with. Do not stop a prescribed medicine on your own.

Always talk with your pharmacist or doctor before making changes to your medications or supplements, particularly if you take several medications or have an ongoing health condition.

1,3-dmaa safety at a glance

1,3-dmaa overall Avoid DMAA is banned in supplements in many countries and tied to serious cardiovascular harm.
Pregnancy Avoid It is an unsafe stimulant with no safety data; do not use during pregnancy.
Breastfeeding Avoid No safety data and known stimulant risks; do not use while breastfeeding.

Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Still wondering about combining Lapatinib and 1,3-dmaa? Ask Dr. Brian Staiger, PharmD, BCPS directly ›
How we checked

Why No Interaction Is Listed for Lapatinib

Interactions in our licensed database are recorded against drug classes, not just single drug names. Lapatinib is filed under 3 classifications — cytochrome p450 3a4 (cyp3a4) inhibitors, cytochrome p450 3a4 (cyp3a4) substrates, oral drugs. 1,3-dmaa has documented interactions with 2 drug classes — the most serious being cytochrome p450 2d6 (cyp2d6) substrates (moderate) and stimulant drugs (moderate) — and none of Lapatinib’s classifications are among them.

Classification data comes from our licensed Natural Medicines dataset. A medication can belong to classes beyond those recorded there, so this describes how the check was run — it is not a safety guarantee.

Keep it in perspective

1,3-dmaa Does Interact With Other Medications

1,3-dmaa has 321 moderate known drug interactions in our database — Lapatinib isn’t one of them. If you take anything else, check it against the full list below.

Moderate 321 No known interaction 2,509 (incl. Lapatinib)
Taking anything else?

Check Another of Your Medications Against 1,3-dmaa

Covers the 2,830 medications we’ve checked against 1,3-dmaa. Pick one to open its full report.

What to actually watch for

No Interaction Found — But Data Suggests 1,3-dmaa and Lapatinib May Share Several of the Same Side Effects

This is not an interaction. Neither one changes how your body handles the other, and nothing here says they react together. What our sources do show is that each has separately been linked to the effects below — so taking both can make those effects more likely to turn up, and harder to pin on one or the other if they do.

  • Diarrhea / Vomiting / Nausea reported in 27.1% of FDA reports for Lapatinib Additional detail

    1,3-dmaa

    “Orally, taking 1,3-DMAA combination products (OxyELITE Pro, AmphetaLean, or Jack3d, USPlabs) has been reported to cause cardiac arrest, atrial fibrillation, chest pressure, angina, tachycardia, palpitations, hypertension, hypotension, myocardial infarction, and acute coronary syndrome. Increased heart rate and blood pressure have also been reported.”

    1,3-dmaa · Natural Medicines adverse-effect record, reported in angina.

    6 sources cited
    1. 17660. Adverse Event Report. Jack3d. Natural MedWatch, May 28, 2011.
    2. 91680. Smith TB, Staub BA, Natarajan GM, et al. Acute myocardial infarction associated with dietary supplements containing 1,3-dimethylamylamine and Citrus aurantium. Tex Heart Inst J 2014;41(1):70-2. PubMed
    3. 94361. Archer JR, Dargan PI, Lostia AM, van der Walt J, Henderson K, Drake N, Sharma S, Wood DM, Walker CJ, Kicman AT. Running an unknown risk: a marathon death associated with the use of 1,3-dimethylamylamine (DMAA). Drug Test Anal. 2015 May;7(5):433-8. PubMed
    4. 94362. Armstrong M. Atrial Fibrillation with Rapid Ventricular Response following use of Dietary Supplement Containing 1,3 Dimethylamylamine and Caffeine. J Spec Oper Med. 2012 Winter;12(4):1-4. PubMed
    5. 94365. Brown JA, Buckley NA. Toxicity from bodybuilding supplements and recreational use of products containing 1,3-dimethylamylamine. Med J Aust. 2013 May 6;198(8):414-5. PubMed
    6. 94369. Eliason MJ, Eichner A, Cancio A, Bestervelt L, Adams BD, Deuster PA. Case reports: Death of active duty soldiers following ingestion of dietary supplements containing 1,3-dimethylamylamine (DMAA). Mil Med. 2012 Dec;177(12):1455-9. PubMed

    “Orally, taking 1,3-DMAA-containing combination products has been reported to cause nausea, vomiting, diarrhea, vomiting blood, and abdominal pain.”

    1,3-dmaa · Natural Medicines adverse-effect record, reported in diarrhea.

    6 sources cited
    1. 17907. McCarthy C, Canale RE, Alleman RJ, et al. Biochemical and anthropometric effects of a weight loss dietary supplement in health men and women. Nutr Metab Insights 2012;5:13-22.
    2. 17908. Farney TM, McCarthy C, Canale RE, et al. Hemodynamic and hematologic profile of health adults ingesting dietary supplements containing 1,3-dimethylamylamine and caffeine. Nutr Metab Insights 2012;5:1-12.
    3. 94365. Brown JA, Buckley NA. Toxicity from bodybuilding supplements and recreational use of products containing 1,3-dimethylamylamine. Med J Aust. 2013 May 6;198(8):414-5. PubMed
    4. 94371. Forrester M. Exposures to 1,3-dimethylamylamine-containing products reported to Texas poison centers. Hum Exp Toxicol. 2013 Jan;32(1):18-23. PubMed
    5. 94377. Van Hout MC, Hearne E. "Plant or poison": A netnographic study of recreational use of 1,3-dimethylamylamine (DMAA). Int J Drug Policy. 2015 Dec;26(12):1279-81. PubMed
    6. 17663. Gee P, Jackson S, Easton J. Another bitter pill: a case of toxicity from DMAA party pills. N Z Med J 2010;123:124-7.

    Lapatinib

    Listed in the ADVERSE REACTIONS section of the FDA label for Lapatinib, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

  • Tiredness reported in 8.5% of FDA reports for Lapatinib Additional detail

    1,3-dmaa

    “Orally, taking specific 1,3-DMAA-containing combination products (OxyELITE Pro or Jack3d, USPlabs) has been reported to cause feelings of jitters, sleeplessness, shakiness, chills, sweating, fatigue, tingling, and lack of focus in clinical trials.”

    1,3-dmaa · Natural Medicines adverse-effect record, reported in cluster headache.

    6 sources cited
    1. 17907. McCarthy C, Canale RE, Alleman RJ, et al. Biochemical and anthropometric effects of a weight loss dietary supplement in health men and women. Nutr Metab Insights 2012;5:13-22.
    2. 17660. Adverse Event Report. Jack3d. Natural MedWatch, May 28, 2011.
    3. 17908. Farney TM, McCarthy C, Canale RE, et al. Hemodynamic and hematologic profile of health adults ingesting dietary supplements containing 1,3-dimethylamylamine and caffeine. Nutr Metab Insights 2012;5:1-12.
    4. 94365. Brown JA, Buckley NA. Toxicity from bodybuilding supplements and recreational use of products containing 1,3-dimethylamylamine. Med J Aust. 2013 May 6;198(8):414-5. PubMed
    5. 94368. Dunn M. Have prohibition policies made the wrong decision? A critical review of studies investigating the effects of DMAA. Int J Drug Policy. 2017 Feb;40:26-34. PubMed
    6. 94371. Forrester M. Exposures to 1,3-dimethylamylamine-containing products reported to Texas poison centers. Hum Exp Toxicol. 2013 Jan;32(1):18-23. PubMed

    Lapatinib

    Listed in the ADVERSE REACTIONS section of the FDA label for Lapatinib, and in voluntary FDA adverse-event reports. Read the label on DailyMed ›

Reported for 1,3-dmaa but not commonly for Lapatinib: a heart attack, a fast or pounding heartbeat, an irregular heartbeat and blurred vision.

Effects for Lapatinib come from the ADVERSE REACTIONS section of its FDA label; effects for 1,3-dmaa come from the Natural Medicines adverse-effect record, quoted above. Where a percentage is shown, it is the share of 15,427 voluntary FDA FAERS reports for Lapatinib that mention that effect — a reporting proportion, not an incidence rate and not evidence the drug caused it. Wording is matched across sources by our own clinical vocabulary, so treat this as a prompt to pay attention, not a diagnosis.

Everything else you take

See Every Supplement That Interacts With Lapatinib

This page covers 1,3-dmaa only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Lapatinib page lists 143 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 100 moderate · 40 minor.

From our pharmacist’s overview on the Lapatinib page

“Of the 143 supplements on file for lapatinib (Tykerb), nearly all press on the same point, the CYP3A4 enzyme that clears this HER2-targeted breast cancer drug. That deserves real caution, since lapatinib only works when its blood level stays in range.”

Reviewed by 2 · Jul 18, 2026

Open the Lapatinib interaction page

One more smart check

Taking 1,3-dmaa as Part of a Dietary Supplement Product? Check It for Interactions

We hold 94 real supplement products containing 1,3-dmaa, each one broken down to its full ingredient list — and combination products often carry several ingredients besides 1,3-dmaa. Even though 1,3-dmaa itself has no known interaction with Lapatinib, another ingredient on your label might. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where 1,3-dmaa and Lapatinib Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement 1,3-dmaa
Top half

#485 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Lapatinib
Steady interest

#2,248 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Where does our data come from?
  • Source: the Natural Medicines (TRC Healthcare) clinical database — the evidence-graded professional reference for herb & supplement interactions.
  • Citation library: 103,510 references behind our interaction content, 65,311 of them resolved to verified PubMed/DOI sources. See every 1,3-dmaa reference on this page ↓
  • Freshness: we automatically re-check this combination every week — this pair was last verified September 20, 2026. The 1,3-dmaa and Lapatinib records this page draws on were last updated July 10, 2026.
  • What “no known interaction” means: no documented interaction in the sources above — not a guarantee of safety. Supplements are studied far less than prescription drugs, so we say exactly what the evidence supports, and nothing more.
Data structure & sourcing designed and verified by .
Supplement

About 1,3-dmaa

What is 1,3-dmaa?

1,3-dmaa
  • Energy and stimulation
  • Pre-workout performance
  • Weight loss
  • Appetite suppression
  • Focus and concentration

DMAA (1,3-dimethylamylamine) is a synthetic stimulant that was sold in pre-workout and weight-loss supplements but has been linked to serious harm, including high blood pressure, heart problems, strokes, and deaths. The U.S. FDA and regulators in many countries have declared it illegal and unsafe in dietary supplements, so it should be avoided.

Synthetic compound (not a true plant part); sometimes claimed to come from geranium · Capsules, tablets, pre-workout powders (often as a hidden ingredient)

An interaction check asks whether these two react with each other — it does not ask whether 1,3-dmaa is a good idea for someone in your situation. Here is what our 1,3-dmaa record says about it on its own.

1,3-dmaa: dosing

There is no safe or established dose of DMAA. It is not approved as a dietary supplement ingredient, and we do not recommend taking it in any amount.Because DMAA may be hidden in some products, the safest approach is to avoid pre-workout or weight-loss supplements that list ingredients like dimethylamylamine, methylhexanamine, or Geranamine.

From our 1,3-dmaa monograph — the full record covers uses, side effects and every documented interaction.

Read the full 1,3-dmaa monograph & all interactions
Medication

About Lapatinib

What Is Lapatinib Used For?

Brand name: Tykerb

Lapatinib tablets — sold under the brand name Tykerb — are used to treat advanced or metastatic breast cancer in patients whose tumors overexpress the HER2 protein. They are always used in combination with another medicine, not alone.

Tykerb is approved in combination with capecitabine for HER2-positive advanced or metastatic breast cancer in patients who have already received prior treatment including an anthracycline, a taxane, and trastuzumab, and whose disease has progressed on trastuzumab. Tykerb is also approved in combination with letrozole for postmenopausal women with hormone receptor-positive, HER2-positive metastatic breast cancer when hormonal therapy is appropriate.

Most-Reported Side Effects for Lapatinib

From FAERS, the FDA’s public side-effect reporting system (15,427 reports, all brands). Reports are voluntary and are not proof the drug caused the effect.

Diarrhea 4,174 reports
Nausea 1,615 reports
Fatigue 1,305 reports
Vomiting 1,209 reports
Rash 1,061 reports
See full Lapatinib drug information
Keep checking

Other Drugs & 1,3-dmaa

Browse every other medication we’ve checked against 1,3-dmaa — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
321Moderate
0Minor
2,508No known interaction
321 Moderate 2,508 No interaction
Moderate

321 interactions

Showing 60 of 321 moderate interactions — see all 321 on the 1,3-dmaa page.

No interaction 2,508 drugs checked — show the list

We also checked 1,3-dmaa against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,508 medications checked with no known interaction — see the full 1,3-dmaa list.

See the full 1,3-dmaa interactions page
See every supplement checked against Lapatinib, ranked by severity
Evidence & sources

1,3-dmaa References

The 21 references that drive our 1,3-dmaa monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Adverse Event Report. Jack3d. Natural MedWatch, May 28, 2011.
  2. Gee P, Jackson S, Easton J. Another bitter pill: a case of toxicity from DMAA party pills. N Z Med J 2010;123:124-7.
  3. Removal of the dietary supplement DMAA. Army Medicine, Office of the Surgeon General, 2011. Available at: http://humanperformanceresourcecenter.org/dietary-supplements/files/dmaa-pdf. (Accessed 4 January 2012).
  4. McCarthy C, Farney TM, Canale RE, et al. A finished dietary supplement stimulates lipolysis and metabolic rate in young men and women. Nutr Metab Insights 2012;5:23-31. PubMed
  5. McCarthy C, Canale RE, Alleman RJ, et al. Biochemical and anthropometric effects of a weight loss dietary supplement in health men and women. Nutr Metab Insights 2012;5:13-22.
  6. Farney TM, McCarthy C, Canale RE, et al. Hemodynamic and hematologic profile of health adults ingesting dietary supplements containing 1,3-dimethylamylamine and caffeine. Nutr Metab Insights 2012;5:1-12.
  7. Young C, Oladipo O, Frasier S, et al. Hemorrhagic stroke in young healthy male following use of sports supplement Jack3d. Mil Med 2012;177(12):1450-4. PubMed
  8. Smith TB, Staub BA, Natarajan GM, et al. Acute myocardial infarction associated with dietary supplements containing 1,3-dimethylamylamine and Citrus aurantium. Tex Heart Inst J 2014;41(1):70-2. PubMed
  9. Liu Y, Santillo MF. Cytochrome P450 2D6 and 3A4 enzyme inhibition by amine stimulants in dietary supplements. Drug Test Anal. 2016;8(3-4):307-10. PubMed
  10. Archer JR, Dargan PI, Lostia AM, van der Walt J, Henderson K, Drake N, Sharma S, Wood DM, Walker CJ, Kicman AT. Running an unknown risk: a marathon death associated with the use of 1,3-dimethylamylamine (DMAA). Drug Test Anal. 2015 May;7(5):433-8. PubMed
  11. Armstrong M. Atrial Fibrillation with Rapid Ventricular Response following use of Dietary Supplement Containing 1,3 Dimethylamylamine and Caffeine. J Spec Oper Med. 2012 Winter;12(4):1-4. PubMed
  12. Bloomer RJ, Farney TM, Harvey IC, Alleman RJ. Safety profile of caffeine and 1,3-dimethylamylamine supplementation in healthy men. Hum Exp Toxicol. 2013 Nov;32(11):1126-36. PubMed
  13. Brown JA, Buckley NA. Toxicity from bodybuilding supplements and recreational use of products containing 1,3-dimethylamylamine. Med J Aust. 2013 May 6;198(8):414-5. PubMed
  14. Dolan SB, Gatch MB. Abuse liability of the dietary supplement dimethylamylamine. Drug Alcohol Depend. 2015 Jan 1;146:97-102. PubMed
  15. Dunn M. Have prohibition policies made the wrong decision? A critical review of studies investigating the effects of DMAA. Int J Drug Policy. 2017 Feb;40:26-34. PubMed

Medication overviews come from MedlinePlus (NIH); supplement label data from the NIH Dietary Supplement Label Database. Content is written and reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.

Pharmacist Counseling Corner

Taking 1,3-dmaa and Lapatinib Together: Common Questions

Is it safe to take 1,3-dmaa with Lapatinib?
We do not list a known interaction between 1,3-dmaa and Lapatinib. That does not guarantee the combination is risk-free, so confirm with your pharmacist or doctor — especially if you take other medications or have a health condition.
Do 1,3-dmaa and Lapatinib have any of the same side effects?
Yes — our sources link each of them separately to 4 of the same effects. That is not an interaction: neither changes how your body handles the other. It does mean that if one of those effects turns up, it can be harder to tell which one is behind it. They are listed on this page with the source behind each.
How was the 1,3-dmaa and Lapatinib combination checked?
Interactions in our licensed database are recorded against drug classes. Lapatinib is filed under 3 classifications, and 1,3-dmaa has documented interactions with 2 drug classes — none of Lapatinib's classifications are among them. A medication can belong to classes beyond those recorded in our dataset, so this describes how the check was run rather than guaranteeing safety.
Does 1,3-dmaa interact with any other medications?
Yes. 1,3-dmaa has 321 documented drug interactions in our database — Lapatinib is simply not one of them. If you take anything else, it is worth checking each one; they are all listed on this page.
Does Lapatinib interact with any supplements?
Yes. Lapatinib has documented interactions with 143 supplements in our database — 1,3-dmaa is not one of them. The Lapatinib interaction page linked on this page lists every one, ranked by severity.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

Where next

Keep Exploring

1,3-dmaa monograph Uses, safety profile, and every drug interaction in one place Lapatinib drug information The full plain-English guide to this medication Lapatinib supplement interactions Every supplement checked against Lapatinib, ranked by severity Supplement interaction checker Check any supplement or product against your medications Browse medications A–Z Every drug we’ve checked against herbs & supplements References The 21 citations behind this page Ask a pharmacist Free, personal answer from our licensed team

Still Have a Question About Lapatinib and 1,3-dmaa?

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.